BackgroundThis project evaluated whether practice change occurred amongst Paramedics directly after the publication of the PARAMEDIC2 trial, regarding adrenaline administration during out-of-hospital cardiac arrest (OHCA) without a change in guidelines. When Paramedics are exposed to a seminal publication there is anecdotal concern their autonomous practice changes, based on comprehension of findings ahead of potential guideline changes, however little evidence appraises whether this really occurs.MethodsA service evaluation to determine any variation in adrenaline administration during OHCA, before and after publication of the PARAMEDIC2 trial.WMAS electronic patient record data that has been collected for use within OHCA ambulance quality indicators was used to evaluate practice variation.Proportion of adult patients receiving adrenaline, number of administrations and time to first administration from EMS arrival (or arrest if EMS witnessed) are reported.This evaluation assesses from the day after recruitment ended on 18th October 2017 until the trial results publication on 19th July 2018, and the same timeframe (273 days) post-publication.ResultsProportion receiving adrenalinePre-publication: 88.7% of 3026 casesPost-publication: 88.0% of 2682 casesMean number of adrenaline administrationsPre-publication: 4Post-publication: 4Mean time to adrenalinePre-publication: 30:02 minutesPost-publication: 30:11 minutesConclusionsIn both datasets, average time to first adrenaline administration and number of administrations were found to be similar. This suggests Paramedic practice adheres to current guidelines when a highly anticipated article is published, however this may vary by intervention so further work is recommended. Limitations of retrospective observational evaluations include uncontrolled treatment variables; however randomised controlled trials cannot assess standard practice. Individuals need continued awareness for implications of changing practice following a trial publication, as patient safety could be breached whilst the wider medical community are scrutinising the trial results. This demonstrates how routine data can be used to evaluate practice and changes within it.